At the new Three Dog Bakery in Bethesda, they sell peanut-topped ice cream treats for dogs at 2 1/2 bucks a throw, fresh-baked bone-shaped birthday cakes for $18 and "Petits Fours," which are miniature cakes dipped in carob sauce and topped with swirls of low-fat honey yogurt frosting, two for $1.50.

"Every day people come in and they think these pastries are for people," says Denise Graybill-Donohoe, 42, the bakery's owner. "They get this dumb look on their face and they say, 'This is for dogs?' "

Yes, she tells them, it is for dogs.

And dogs love the stuff. They gobble up these treats as if they were, well, bags of the neighbors' garbage or half-rotten squirrel carcasses.

Let's face it, dogs aren't gourmets or health food freaks. Dogs will scarf up anything--grass, sticks, chicken bones, bologna garnished with green mold. Dogs eagerly chow down on the little treats that cats leave in their litter boxes. And they've been known to climb into diaper pails to gnaw, with visible glee, on dirty Pampers. Long before the advent of the kitchen sink, the dog was man's best garbage disposal.

Does this mean that gourmet dog pastries are a tad ridiculous? Maybe, but they're certainly popular. There are now 29 Three Dog Bakeries in North America. Within a month, there will be eight more. "It's a multi-multi-multi-million dollar company," says Daniel Dye, co-founder of the Kansas City-based chain.

Obviously, humans--a group that constitutes 100 percent of the chain's paying customers--enjoy patronizing these bakeries. But do dogs really prefer eating this stuff? Would they choose these healthy gourmet pastries over traditional dog delicacies, such as dried-up old McDonald's hamburgers? The crack Washington Post investigative team decided to find out.

The Post gathered a smorgasbord of canine treats, then assembled a group of five Rockville dogs and ran a quasi-scientific taste test. The treats were set on plates on the lawn in a typical suburban back yard. From the Three Dog Bakery, there were "Petits Fours," slices of the bone-shaped birthday cake, plus rib-shaped barbecue-flavored crackers. There were also old, cold McDonald's hamburgers, hunks of Spam, traditional Milk-Bone dog biscuits, slices of a strawberry-and-cream cake purchased at Sutton Place Gourmet, and, purely in the interest of science, a plate of cat feces dusted with a confection of kitty litter, and a freshly-soiled Pamper.

The methodology was simple: One at a time, each dog was paraded past this buffet line by its owner so it could smell each of these delicacies. Then the dog was permitted to head for whatever treat it chose. The scoring was also simple: Each dog's first choice earned three points, its second choice earned two points, the third choice one point. The winner would be the food that earned the most points.

Unfortunately, due to the outdoor laboratory venue, the dogs were unable to clear their palates between courses with a swig of eau de toilette.

The first dog down the line was Maggie, 9, a miniature schnauzer. Led by her owner, Dorothy Sullivan, Maggie headed right for the Spam. She sniffed it and quickly moved on to the McDonald's burger, which she promptly wolfed down. After that, she returned to the Spam and gobbled it up. Then, apparently eager for dessert, she ate half a portion of the bone-shaped Three Dog Bakery cake, sashayed over to the Sutton Place strawberry cake, sniffed it, turned up her little nose and returned to finish up the dog cake.

"She likes that bone cake," said Sullivan.

The next dog was an 8-year-old pug named Otis. Led by owner Leah Ensor, Otis sniffed a Three Dog Petit Four, rejected it and headed right for the Spam, which he scarfed down before gobbling up the McDonald's burger. After that, he took a quick nibble on the Three Dog bone cake and then ate a Milk-Bone biscuit, followed by a Three Dog BBQ cracker. Then he returned to the now-empty Spam plate, which he licked forlornly, obviously eager for more.

Next came Jamie, 3, a female beagle who has recently developed a taste for dirty underwear. "Everyone in the family now has crotchless panties," joked her owner, Deborah Gervasio.

Jamie headed for the Spam, gave it a quick lick and then moved on. She licked the bone cake, then sniffed the cat litter, then returned to the Spam and devoured it in one bite. Finally, she strolled over to the Sutton Place strawberry cake and ate it with obvious glee.

"Smart dog!" Gervasio said proudly. "It was a balanced meal--Spam and some cake."

Next, Martin Corley led K.C., his 7-year-old keeshond, down the buffet line. K.C. sniffed at the Pamper, exhibiting some interest, and then quickly scarfed down a Petit Four, followed by some Spam and a McDonald's burger.

The last contestant was a mutt named Chelsea, 11. Led by owner Caitlin Carlson, Chelsea, a notorious diaper-chewer, headed straight for the Pamper. She sniffed it, but didn't bite. Instead, she moved to the bone cake, which she eagerly gobbled up. Then she ate a McDonald's burger, followed by a Three Dog BBQ cracker. She passed up the cat litter and the Sutton Place cake and chomped down the Spam. Apparently, she liked Spam: A moment later, when she thought nobody was watching, she climbed up on a table and devoured the rest of it.

She had picked the winner. Spam took the title with 10 points, followed closely by McDonald's with eight. The bone cake was a distant third with four points, followed by the Petit Four with three.

None of the dogs had eaten any cat litter or nibbled on the Pampers. This spoke volumes about their good breeding and delicate sensibilities, although there was some speculation that the beasts' embarrassed owners had yanked a little harder on their chains when they showed interest in these unsavory delicacies.

Graybill-Donohoe, the bakery owner, was disappointed in the results. "The dogs you chose didn't have discerning taste, I guess," she said, laughing. "You could say they were like kids who prefer candy to liver and peas or whatever their parents think is good for them."

"Dogs, given a choice, are much like Americans: They prefer junk food," said Dye, the Three Dogs co-founder, when he learned of the test results.

"You've given us some ideas for future products, though," he added. "We've got to do something with Pampers. Or maybe a Spam biscuit. I've already contemplated making a dead-squirrel pie."

CAPTION: Four of the five participants in the taste test line up, waiting for the buffet to be laid out.

CAPTION: An 11-year-old mutt named Chelsea, above, and an 8-year-old pug named Otis, far left, both enjoyed a variety of the taste test foods, including Spam and a McDonald's hamburger. Chelsea also enjoyed the bone-shaped birthday cake from Three Dog Bakery, near left, but, alas, the cake came in a distant third with four points. The winner? Spam, by more than a lick.

Chich gourmet delicacy would your dog choose?

* A bone-shaped doggy birthday cake that costs $18?

* An old McDonald's hamburger that has been left out in the sun?

* Spam?

* Milk-Bone dog biscuits?

* A yuppie strawberry-and-cream cake?

* Cat feces lightly dusted with kitty litter?

* A freshly soiled Pamper?